Method and switching arrangement for identifying the charger of rechargable batteries of portable devices

ABSTRACT

The object of the Invention is a method and a switching arrangement for identifying the charger of the rechargeable batteries of portable devices. In the solution according to the invention the charger transmits the identification of the charger via a charging cable by switching the charging voltage on and off by using a certain pulse ratio, pulse length, or pulse count. The solution according to the invention can be applied in mobile phone sets.

FIELD OF INVENTION

The present invention relates to identification apparatus and a methodtherefor.

In particular, it relates to apparatus and method for accessory devicesof electronic devices such as portable telephones.

BACKGROUND TO INVENTION

There are many types of peripheral devices used with electronic devices.A particularly common accessory device is a battery charger for portabledevices such as portable telephones The present invention will now bediscussed in terms of the state of the art and by way of example, withreference to battery chargers.

There are a number of known methods for charging rechargeable batteriesfor portable devices, such as nickel-cadmium batteries. Many of thesechargers require the removal of the batteries from the device to enablerecharging. Removal of the batteries from the device is considered adrawback, since the device is out of operation during the recharging.However, a number of different chargers have been developed which can beattached to a battery powered device and the batteries charged in situin the device. In this way, the functionality of the device can bemaintained while charging the batteries. Even though the functionalityof the device is maintained, a portable device, such as a mobile phone,is unavailable for operation in the manner intended, i.e., as a portabledevice. Since chargers often recharge a battery using a fairly lowcharging current, the battery powered device is not available forportable operation for extended periods of time, such as eight hours ormore during which time the batteries are being recharged.

Many battery powered devices, such as mobile phones, are extremelyenergy intensive, expending considerable amounts of power during thereceive functions and more particularly during the transmit functions.Because of lengthy recharging times, "rapid" chargers have beendeveloped which can charge batteries fairly rapidly, for example In lessthan an hour as compared with the charging time of eight hours forprevious battery chargers.

In order to charge batteries rapidly, numerous problems had to beovercome. One of the most serious problems was overcharging of thebatteries, resulting in turn in the overheating of the batteries.Overheating may damage the battery case seals, resulting in rupturing ofthe battery case and In extreme instances in explosive rupturing of thebattery case.

In known "rapid" battery chargers most of these problems have beensolved in one way or another, e.g., by monitoring given batteryparameters, such as the charging rate of the battery, internal batterytemperatures or charge state of the battery. In some "rapid" chargers,attempts have been made to prevent overcharging of the batteries byutilizing timed charging of the battery. However, using these knownsolutions It Is not always possible to prevent overcharging ofbatteries, for instance, when the charger type is not exactly a correctone or designed to be used with the battery being charged.

Numerous different types of chargers are on the market which comprisedifferent charging capacities and charging parameters for chargingrechargeable batteries of portable devices. Some chargers can even beunsuitable, i.e,, hazardous for the batteries. Consequently, portabledevises should be able to somehow identify the charger and itsproperties. Similar problems exist for accessory devices generally forall types of electronic device, not just battery chargers or portabletelephones.

BRIEF SUMMARY OF INVENTION

According to a first aspect of the present invention, there is providedidentification apparatus for an accessory device, comprising couplingmeans for coupling the accessory device to an electronic device andmodulation means for modulating a signal on the coupling means inaccordance with identity data for the accessory device.

According to a second aspect of the present invention, there is providedan identification method for an accessory device, comprisingtransmitting an Identity signal from the accessory device to anelectronic device coupled thereto by modulating a signal transmittedtherebetween In accordance with identity data for the accessory device.

The present invention provide the advantage that the accessory devicecan indicate to an electronic device to which it is connected whichperipheral device it is. Thus, there is provided a solution to a problemof identifying accessory devices.

In a preferred embodiment the modulation means comprises a switch meansoperable to activate and de-activate the coupling means.

Preferably, the Identification apparatus further comprises a bitgenerator or corresponding charger for generating the identity data.

Suitably, there is provided control means adopted to control themodulation means in accordance with the identity data for superimposinga pulse ratio, pulse length, pulse count or the like signal on the onthe coupling means.

Advantageously, there is provided timing means for determining a timeduring which the modulation means is operable, in particular the timingmeans comprises a timer and a switch operable in accordance with thetimer to decouple the identity data from the control and/or modulationmeans.

Optionally, the switch means comprises a switching transistor or fieldeffect transistor.

Identification may be implemented after a certain start-up period,before operation, e.g. charging, is started or in the initial stage ofoperation of the accessory device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagrammatic illustration of the implementation ofapparatus in accordance with the invention,

FIG. 2 shows a more detailed diagrammatic illustration of the apparatusof FIG. 1

DETAILED DESCRIPTION OF EMBODIMENTS IN ACCORDANCE WITH THE INVENTION

Embodiments in accordance with the Invention are now described, by wayof example only, and with reference to the appended drawings.

In a device in accordance with the invention a battery charger for atransportable device transmits an Identification code for the chargervia a charging cable, by switching the charging voltage on and off usinga certain pulse ratio or pulse length or pulse count. Suchidentification can be implemented after a certain start-up time orbefore starting an actual charging routine It can also be carried out inthe initial stage of charging after having switched the charging on orentered a charging routine.

FIG. 1 shows an implementation of an embodiment in accordance with theInvention. The Identification of the charger is formed by using bitgenerator 1 from which the Identification is taken via switching block2, controlled by timing block 3, to control block 4 of a pulse widthmodulator. A switching transistor or field effect transistor functionsas switch 8 and takes a charging voltage containing the identificationas a modulation imposed thereon, via inductance 6 to the output of thecharger. Timing block 3 can also operate to control switch 8 to stay onafter the pulse identification has been transmitted from the charger,The main circuit comprises, in a known manner, parallel diode 5 andparallel capacitor 7 coupled to ground. The charging voltage may be theoutput of a DC/DC converter, the output of which is then switched on oroff by switch 8.

FIG. 2 shows a slightly more detailed diagrammatic illustration of theapparatus in accordance with the invention. The identification of thecharger is formed by using logic NAND circuit 9 (an AND circuit havingan inverting output), from where the identification is transmitted tocontrol block 4 of the pulse width modulator. The resistances shown inFIG. 2 are marked with numbers 10 and 11 and the capacitors are markedwith numbers 12 and 13. A switching transistor or field effecttransistor functions as switch 8 and takes the charging voltagecontaining the identification via inductance 6 to the output of thecharger. The pulse identification is formed until capacitor 12 ischarged, switch 8 being left switched on thereafter.

In view of the foregoing description it will be evident to a personskilled in the art that various modifications may be made within thescope of the invention. For example, the accessory device need not be abattery charger but could be some other accessory, and the electronicdevice need not be just a portable telephone. Additionally, themodulation of the charging voltage may comprise varying the chargingvoltage as well as switching it on or off.

The scope of the present disclosure includes any novel feature orcombination of features disclosed therein either explicitly orimplicitly or any generalization thereof irrespective of whether or notit relates to the claimed invention or mitigates any or all of theproblems addressed by the present invention. The applicant hereby givesnotice that new claims may be formulated to such features duringprosecution of this application or of any such further applicationderived therefrom.

What I claim is:
 1. Identification apparatus for identifying a chargerdevice for rechargeable batteries of portable electronic devices,comprising a charger device for providing a charging voltage, a low passfilter coupling means connected between the charger device and forcoupling the charging voltage of the charger accessory to the electronicdevice, and modulation means for modulating a signal on the couplingmeans to provide an identification signal in accordance with identitydata for the charger device.
 2. Identification apparatus according toclaim 1, wherein the modulation means includes a switch means operableto activate and de-activate the coupling means.
 3. Identificationapparatus according to claim 1, further including means connected to themodulation means for generating the identify data.
 4. Identificationapparatus according to claim 1, wherein the modulation means includescontrol means connected to the means for generating the identity data tocontrol the modulation means in accordance with the identity data forsuperimposing a pulse ratio, pulse length, or pulse count signal on thesignal on the coupling means.
 5. Identification apparatus according toclaim 1, wherein the modulation means includes a control means andwherein there is further provided timing means connected to the controlmeans of the modulation means for determining a time during which themodulation means is operable.
 6. Identification apparatus according toclaim 5, wherein the timing means comprises a timer and a switchoperable in accordance with the timer to decouple the identity data fromthe control means.
 7. Identification apparatus according to claim 2wherein the switch means comprises a switching transistor or fieldeffect transistor.
 8. Identification apparatus according to claim 4further including:a logic NAND circuit connected to said control meansfor providing identity data to the control means., a first resistancemeans, and a first capacitance means connected to one input of the NANDcircuit and a second resistance and a second capacitance connected toanother input of the NAND circuit, wherein the identity data is formedby using the logic NAND circuit, from where the identity data is coupledto the control means for a pulse width modulator.
 9. An identificationmethod for a charger device, comprising transmitting an identity signalfrom the charger device to an electronic device coupled thereto bymodulating a signal transmitted between the charger device and theelectronic device in accordance with identity data for the chargerdevice.
 10. A method according to claim 9, wherein the identity signalis modulated by switching the identity signal on or off. 11.Identification apparatus according to claim 3 wherein said means forgenerating the identity data is a bit generator.
 12. Identificationapparatus according to claim 3 wherein said means for generating theidentity data is a charger device.
 13. A method for identifying acharger device providing a charging voltage for rechargeable batteriesof portable devices, characterized in that the charger device transmitsan identification of the charger device to the portable device via acharging cable by switching the charging voltage on and off by usinggiven pulse ratio, pulse length or pulse count signals.